CN1177110C - Eccentric device for vibration piling hammer - Google Patents

Abstract

The present invention discloses an eccentric device for a vibration piling hammer. The eccentric device for a vibration piling hammer is provided with an eccentric body (4) and an eccentric shaft (5). The present invention is characterized in that the eccentric body (4) is installed on the eccentric shaft (5), a spring hole (9) is arranged on the eccentric shaft (5), and a spring (6) is arranged in the hole of the eccentric shaft; a reserved distance (L0) exists between the centroid (7) of the eccentric body and the center (8) of the eccentric shaft. The spring which is arranged in the spring hole of the eccentric shaft is adopted by the present invention; when the present invention operates, the generated length deformation amount enables the centroid of the eccentric body to move corresponding to the position of the eccentric shaft, and then, the values of the eccentric torque are changed from a small value to a large value; thus, the purpose of starting in a zero load is realized. The present invention has the advantages of simple structure, scientific design, low electric energy consumption, high efficiency and low cost; the present invention can bring positive use effect and social benefit for construction of building engineering, and is a preferred device for building engineering.

Description

A kind of eccentric of vibropiling hammer

Technical field

What the present invention relates to is a kind of pile hammer of constructional engineering machinery, particularly be the improvement invention of a kind of vibropiling hammer, what be specifically related to is the invention of pile hammer eccentric.

Background technology

In the prior art, the basic principle of the eccentric of vibropiling hammer be use centrifugal force that a pair of above eccentric body that is fixed on two synchronous reversing shafts produces under certain rotating speed with joint efforts (claiming exciting force again) make vibrator at vertical vibration, realize the purpose of vibropiling, the centrifugal force that the is produced P=k ω that makes a concerted effort ²Cos (ω t)/g=Lm ω ²Its K=Lmg of cos (ω t), it is eccentric moment, L is the eccentric throw of eccentric body with respect to the axle center, m is the quality of eccentric body, ω is the angular velocity of eccentric shaft, t is the time, the eccentric of this vibropiling hammer, owing to action of gravity, the barycenter of eccentric body must be below eccentric shaft at prestart, make its starting rotation, the essential starting power that consumes motor, and this is that a kind of fullcharging carries starting, because the rotation of eccentric body is to start from scratch, power consumption is very big during starting, the vibrating hammer starting current of real work surpasses seven times of normal current, seriously influences the stable of electric network source, and consumes energy, sometimes also can be difficult to starting because electric network source power is low, so it must inform that when dispatching from the factory near the transformer capacity its building site of user must for solving starting difficulty, exceed much than actual operate as normal desired power when selecting power of motor greater than more than four times of power of motor, the utilization rate of power of motor is reduced greatly, virtually consumes energy.Recent decades, people's attempt is developed a kind of existing in zero loading status starting, the eccentric of vibropiling hammer simple in structure again, that efficient is high, cost is low.Therefore just produced a kind of vibrating hammer of zero load starting in Japan, its structure is that each eccentric body all is divided into identical two half of shape size, wherein be fixed on for half on the eccentric shaft, can on eccentric shaft, move for half in addition, at the vibrating hammer prestart, utilize the complicated attachment device of a cover, make the symmetric position that can be positioned and be fixed on half eccentric body on the eccentric shaft at half eccentric body that moves on the eccentric shaft, reaching total eccentric moment is zero, actuating motor then, after rotating speed reaches operate as normal, utilize attachment device that mobile half eccentric body is moved to half eccentric body of dead axle again and merge into integral body.Reach the eccentric moment of designing requirement, the vibrating hammer of this zero load starting has solved the problem of full load starting, but the complicated attachment device of one cover, manufacture difficulty height, cost height, maintenance difficult and start the part power that attachment device takies motor again, its price exceeds more than three times of identical ability to work vibrating hammer, so fail to bring social benefit to the building engineering construction industry.

Summary of the invention

In view of the problem that known technology exists, purpose of the present invention aim to provide a kind of simple in structure, energy consumption is low, noise is low, easy to manufacture, easy to maintenance, cost low and the eccentric of vibropiling hammer that can zero load starting.For achieving the above object, the present invention finishes as follows: the eccentric of this vibropiling hammer, have eccentric body and eccentric shaft, described eccentric shaft is square, described eccentric body is installed on the square eccentric shaft, have spring eye on the described eccentric shaft, be provided with spring in the hole of described square eccentric shaft, the barycenter of described eccentric body and the center of eccentric shaft have the reservation distance, this reservation distance approaches neck, the precompression of described spring square shaped eccentric shaft is greater than the weight of eccentric body, make the center of the barycenter of eccentric body near eccentric shaft, the centrifugal force when the eccentric body operate as normal of the eccentric of vibropiling hammer and the weight sum of eccentric body are greater than the precompression of described spring to eccentric shaft, and when it approached operate as normal, the displacement of eccentric body barycenter was tending towards the equilibrium,transient state.The present invention uses the spring that places in the square eccentric shaft spring eye, the eccentric body position is for the relative displacement of the center of eccentric shaft during its work, realize the purpose of zero load starting, during from whole starting process to operate as normal, do not need other attachment devices and additional power, and after the overall structure of vibrating hammer adopts vibration damping noise reduction measure, vibrating hammer with low noise environment-friendly function, it is simple in structure, design science, the electric energy consumption rate is low, and cost is low, will bring positive result of use and social benefit to building engineering construction, be the preferred unit of construction work industry.

Description of drawings

The present invention has following accompanying drawing:

Fig. 1 is a prior art constructions cross-sectional schematic of the present invention;

Fig. 2 is the lateral view of prior art prestart eccentric body of the present invention;

Fig. 3 is the sectional view of prior art prestart eccentric body of the present invention;

Fig. 4 is the lateral view of prior art starting of the present invention back eccentric body;

Fig. 5 is the prestarting structure cross-sectional schematic of the present invention;

Fig. 6 is the prestarting elevation of the present invention;

Fig. 7 is the sectional view after the present invention starting

Fig. 8 starts the back elevation for the present invention.

Half eccentric body of 1 expression prior art among the figure, the eccentric body identical in the 2 expression prior aries, the eccentric shaft of 3 expression prior aries with 1 shape.

The specific embodiment

Accompanying drawing has been represented structure of the present invention and embodiment, describe each relevant details and principle thereof of embodiment below more in conjunction with the accompanying drawings in detail, the eccentric of this vibropiling hammer, have eccentric body 4 and eccentric shaft 5, described eccentric shaft 5 is a rectangle, eccentric body 4 is installed on the rectangle eccentric shaft 5, in the spring eye 9 of rectangle eccentric shaft 5, be provided with spring 6, at prestart eccentric body 4 position such as Fig. 5, Fig. 6 with eccentric shaft 5, the precompression F0 of 6 pairs of eccentric shafts 5 of spring makes center 8 positions of the barycenter 7 of eccentric body 4 near eccentric shaft 5 greater than the weight mg of eccentric body 4.For convenience of description, present embodiment is represented the relation of various computings with formula.The precompression F of 6 pairs of eccentric shafts 5 of above-mentioned spring ₀Be expressed as F with formula ₀=PX ₀Its P represents the rigidity of spring 6; X ₀The length deformation amount of expression spring 6 after beginning to start, is given the eccentric throw L that stays ₀Centrifugal force when beginning to start is P ₀, according to the relational expression P of centrifugal force and eccentric body angular velocity ₀=L ₀M ω ₀ ², ω wherein ₀The angular velocity of expression eccentric body when beginning to start.Because L when design ₀Very little, and approach zero, required power W when beginning to start ₀=L ₀Mg ω ₀ ²Also approach zero, work as W ₀When approaching zero, power required when it begins to start also approaches 0, so the present invention is zero load starting.Present embodiment makes the precompression F of spring 6 when design ₀Greater than the weight of eccentric body 4, i.e. F ₀＞mg has very little centrifugal force P when beginning to start ₀, but the barycenter of eccentric body 4 is subjected to displacement, still keeping the state of zero load starting, along with the increase of angular velocity omega, centrifugal force also and then increases, and when angular velocity increases to when approaching operate as normal speed, the angular velocity of establishing this moment is ω _i, i.e. its centrifugal force P _i=L ₀M ω _i ², the centrifugal force P when it approaches operate as normal _iEqual the precompression F of spring with the weight mg sum of eccentric body ₀The time, i.e. P _i+ mg=F ₀, this moment, the center 8 of eccentric body 4 barycenter, 7 displacements and eccentric shaft 5 was tending towards the equilibrium,transient state, and when the angular velocity of eccentric body 4 increases to greater than near the angular velocity of operate as normal the time, establishing angular velocity at this moment is ω, i.e. ω＞ω _i, at this moment, the centrifugal force P of eccentric body 4 is the centrifugal force P greater than near operate as normal the time also _i, the weight mg sum of centrifugal force P and eccentric body 4 is greater than spring 6 precompression F simultaneously ₀, i.e. P+mg＞F ₀, spring 6 shortens owing to being subjected to action of centrifugal force, and the length deformation amount is by X ₀To X, following eccentric body 4 barycenter eccentric throws by L ₀Move on to L, the increment of its eccentric body 4 barycenter displacements is L-L ₀=X ₀-X, and the increment of spring pressure and centrifugal force is respectively Δ F=P (X ₀-X) and Δ P=(L-L ₀) (ω ²-ω _i ²) m, the increment Delta F of spring pressure is directly proportional with the length deformation amount of spring, and the centrifugal force increment also is directly proportional with barycenter 7 displacement increments of eccentric body 4, and be directly proportional with the difference of two squares of angular velocity, barycenter 7 disequilibriums of while eccentric body 4, at this moment, the displacement that the position of eccentric body 4 barycenter produces, reach the eccentric throw of designing requirement, make exciting force (being centrifugal force) also reach designing requirement simultaneously.In the foregoing description, L and P are eccentric body barycenter eccentric throw and the centrifugal force that reaches designing requirement.

The eccentric of vibropiling hammer of the present invention is the starting process of zero load in whole starting process, during extremely near the operate as normal rotating speed, increases load continuation starting and arrives piling working speed and working load.The described eccentric throw L that stays that gives ₀Present embodiment is defined as L through construction test ₀＜0.05L, it is ω that the definite value of eccentric body angular velocity is closed _i＜0.95 ω.According to the eccentric that the vibropiling of design motif made of the present invention is hammered into shape, bring positive result of use will for the building engineering construction industry, compared with prior art have substantive distinguishing features and obvious improvement.

Claims (2)

1, a kind of eccentric of vibropiling hammer, have eccentric body and eccentric shaft, it is characterized in that described eccentric body (4) is installed on the eccentric shaft (5), have spring eye (9) on the described eccentric shaft (5), described eccentric shaft (5) is square, be provided with spring (6) in the spring eye (9) of described eccentric shaft (5), described spring (6) is to the precompression of eccentric shaft (5) weight greater than eccentric body (4), the barycenter (7) of described eccentric body (4) has the reservation distance with the center (8) of eccentric shaft (5), and this reservation distance approaches zero.

2, the eccentric of vibropiling hammer according to claim 1, the centrifugal force when it is characterized in that eccentric body (4) operate as normal is greater than the weight sum of spring (6) to the precompression and the eccentric body of eccentric shaft (5).

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